There are two primary ways to remove advertisements from your site:

1. Set up a PayPal subscription for the site, either through the 'Remove Ads' link under the right column ad or on on the Admin Menu -> Billing -> Setup Subscription link.
2. Make a one-time contribution through a Crowd Pay widget on your site.

Both of these options require making a payment to proceed.  Once it is processed through PayPal, the system will remove the advertisements from the site (as well as add the rest of our paid functionality).

There is not an option for an admin with an ad-supported site to choose the type of ads or move the banners on the site.  The ads can be removed in their entirety with a payment, but not moved.